Grass shears with push rod rollers



Feb. 23, 1954 Q w, KAHL 2,669,830

GRASS SHEARS WITH PUSH ROD ROLLERS 7 Filed Jan. 9, 1953 INVENTORPatented Feb. 23, 1954 UNITED STATES PATENT OFFICE GRASS SHEARS WITHPUSH ROD ROLLERS Carl H. William Kalil, Phoenix, Ariz.

Application January 9, 1953, Serial No. 330,496

2 Claims.

This invention relates to grass shears operated with a minimum offriction, equipped with a shock absorber, and improved by a body weightappliance.

Hand-operated shears are still in use, but fingers get cramped, blistersdevelop, and the work progresses slowly. Larger shears, for two-handedoperation, with arms extended, wear a man out. Other apparatus withmechanical transmission are being operated from a standing posture, butthey are either handicapped by excess friction or a blunt mechanism thattaxes the strength of the operator.

In view of the foregoing, the first object of my device is to enable aman to use these grass shears without having to kneel down.

Another object is to eliminate the use of hand pressure, and, instead,to bring ones arms and body weight into play for pushing the shearsshut.

Another object is to provide shears with longer and more powerful bladesthan those operated by single hand pressure and still retain a smoothlyworking apparatus that will not tire the operator.

Still another object is to equip this cutting device with a plungerwhich requires but a short stroke, so that the operator may get resultsby short, swift jabs upon the plunger, with arm motion and little backbending.

Another objective is to create a device which is simple in construction,easily fabricated and at no great cost.

Still another object is to all but eliminate friction within themechanical transmission of the power obtained through the plunger.

Another object is to eliminate the shock which is incurred in certaindevices which are designed to ram a push rod against a solid metal unit,such as a lever or a bell crank. Instead, my object is to construct asmoothly rolling propulsion device which exerts cumulative pressure uponthe shear arms.

Another object is to eliminate a second shock, harmful to the wholemechanism. This shock is incurred when the propulsion device ispermitted to slam the shear arms together or against a post. My objectis to install a bufier, a shock absorber, in order to hold wear and tearof the com ponent parts down to a minimum.

I attain the foregoing objectives by means of the devices andconstruction illustrated in the accompanying drawings, in which Figure 1is a perspective view of the assembled apparatus, standing upright uponits metal base.

Figure 2 is a side elevation of the lower part of the device, affordinga view of the shears connected to the metal base and to the propellingrods.

Figure 3 is a back elevation of the device, without the guard and thetoe strap.

Similar numbers refer to similar parts in the several views.

Referring to the drawings, Figure 1 shows the complete assembly of theapparatus, which includes a pair of metal shears I, mounted on a metalbase 2, with sides 20 bent down at right angles. The sides iii) of saidmetal base taper up to the front to permit a tilting of the shearblades. The king bolt 3 of the shears is replaced by a longer bolt 3 topenetrate both the shears and the base plate, with a nut 4 below. Aspring 5 holds the shear arms 2! apart.

An operating mast 6 (pipe) leaning slightly backwards, is fastened in asocket 7 which is riveted or welded upon the base plate. Halfway up themast, two rods 8, hinged by loose bolt connection 22, reach downward forinsertion into holes 9, drilled in the ends of the shear arms.

-; These rods 8 are the propelling rods.

A plunger it! is attached to a carriage H, with two grooved wheels 12,which are designed to roll partway down the said propelling rods andcause the shears to close. The opening 9 in the shear arms must permit asliding motion of the rod ends, because, when being pressed together,the rod ends describe an arc downward, while the shear arms move on ahorizontal plane.

A guide slot l3, across the base plate, is provided to steady themovement of the shear arms.

The plunger 10 extends downward below the carriage II to form a buffer14 which will strike the base plate at the end of the downward stroke,thus taking the shock oir the rods and the shear arms. The plunger isequipped with a guide bracket l5, steadying it by sliding up and downthe mast.

Two light springs It connect the top of the mast with the carriage I lfor the pull back up.

A stop collar ll, near the top of the mast, checks the upward stroke.

An upright metal guard l8, behind the mast, prevents the operators toefrom getting under the buffer.

A toe strap i9 is added for pushing the device about.

The construction of this apparatus is very simple, and its function canbe grasped at a glance.

' The manipulation of the cutters is so easy and the leverage sopowerful that long blades may be used.

When the assembly is made as above stated, the operation of the shearsis accomplished by short downward jabs upon the plunger. There is nojarring start and no jerky mechanism. The carriage with its two groovedwheels gets under way smoothly, in a gliding motion, with cumulativeforce and little friction. And since the propelling rods are hooked upto the shear arms, the latter move simultaneously, and the shears snapshut.

There is no deep plunge involved, and therefore little back bending; forthe shears close when the grooved wheels have tracked only halfway downthe propelling rods.

The closing of the shears is timed by the length of the buffer. Thisshock absorber is merely an extension of the plunger, below thecarriage, and is designed to hit the base plate at just the right timeto close the shears fully and yet prevent the shear arms from hittingtogether. In this manner the shock upon the mechanism is diverted fromboth the propelling rods and the shears,- and is absorbed-by the morerobust plunger. Also a good deal of friction is eliminated by theinstallation of this huifer, and the operator may push the plunger asvigorously as he desires.

The plunger and carriage are pulled back up by the springs from the masttop. The stop collar, near the top of the mast, halts the plunger on itsway up.

Due to the short travel of the plunger, the opening and the shutting ofthe blades can be repeated rapidly and without great .eiiiort.

For cutting grass or weeds closer to the ground, :the apparatus may betilted forward. The tilting is facilitated by two factors: the sides ofthe base plate tapering forward, and a lift on the toe strap to supportthe tilt.

A powerful leverage is exerted upon the shear arms as the plunger forcesthe grooved wheels down the propelling rods; and the cutting of grassand weeds is accomplished by a decisive force; yet, due to the wheelingmotion and the cumulative pressure obtained in this device, no

great muscular eiiort is required to operate it.

I claim: '1. Grass shears comprising a ground-contacting base plate;shears mounted upon said plate r outwardly, their lower ends fittinginto holes drilled into the ends of the said shear arms;- a

metal guide bracket fastened to the said base plate to cover the pathand to steady the movement of the said shear arms; a double-rod plungerwith a two-fist grip handle and a guide bracket slideably mounted on thesaid mast, one of the said plunger rods being positioned on either sideof said mast; two small pulley wheels'laterally disposed on axles withina rectangular metal frame attached to the said plunger rods; the saidmast being positioned inside. the said rectangular frame, one of thesaid pulley wheels being positioned on either side of said mast, eachone of said pulley wheels being provided with a rim groove fittingsnugly upon the outer face of one of the .said propelling rods, the saidwheels being spaced close together within the said rectangularfgrameandiso arranged that downward motion of the said plunger will cause thesaid wheels to track down on the said diverging rods, closing in onthem, forcing the lower ends of the said rods together towards the saidmast and causing the said shear arms to close.

2. Ina grass shears; a vertically dis-posed mast rigidly secured upon ametal base plate; shears mounted at the front end of the said baseplate, one shear arm being positioned on either side of said mast; aplunger attached to aguide bracket slideable upon the said mast; anextension at the bottom of the said plunger, forming a buffer stopandserving as'a shock absorber of the shearing device, the impact of thesaid plunger extension against the said base plate being synchronizedwith the closing of the said shear arms, averting a clanking together ofthesaid shear arms or a slamming of the said shear arms against the saidmast, said buffer taking the off the more delicate mechanisinof thisdevice, reducing wear and tear; an upright metals'hield fastened uponthe said base plate, right behind the point of contact with the saidbutler preventing the operators toe from getting under the said bufier;a leather shoe strap doming the rear of the said base plate and fastenedthereto; a stout steel spring between the said shear arms; forcing theshears to reopen; a stopcollarset at a point on the said mast to limit'thereturn move of the said plunger; and two springs from; the top of thesaid mast to thesaid guide bracket of the said plunger. toeasethe returnmove of the" said plunger. l w

CARL H.

References Cited in the file of this patent UNITED STATES PATENTS Number

